Project Summary/Abstract Vocabulary learning is a pervasive and persistent problem for individuals with language impairment (LI). This challenge has meaningful consequences as vocabulary knowledge is related to academic success, occupational status, and social functioning. To provide effective vocabulary interventions, it is vital that we understand how the cognitive mechanisms underlying LI contribute to vocabulary learning. There is robust evidence that impaired short-term and working memory are primary barriers to word learning for individuals with LI. However, we lack an understanding of potential retention deficits, as the ability to retain taught material is rarely measured weeks, months, or years post-training. Relatedly, training strategies have differential effects on short-term and long-term retention for children with typical development (TD). However, we know little about how these strategies affect children with LI as long-term retention is rarely assessed. Given the time that clinicians, parents, and children invest in interventions and their potential lifelong benefits, it is essential that we determine the most effective and efficient training strategies to foster long-term retention of children with LI. To address these gaps in the knowledge base, the broad objective of this research program is to improve the retention, generalization, and integration of words for children with LI. The current project focuses on understanding and improving retention through the following specific aims. 1-To compare learning and forgetting rates of words by children with and without LI, and 2-To identify the aspects of training that enhance long-term retention of words by children with LI. The research strategy involves two experiments in which children with and without LI are taught novel word-object pairs and then tested across various retention intervals (e.g., two weeks, one month). Two aspects of training show robust effects on long-term retention in typical populations will be assessed in children with LI, timing of exposures and type of engagement with materials. The effect of these factors on the retention of words by children with LI will be assessed. This research will advance our understanding of the cognitive mechanisms underlying language impairments by identifying whether children with LI have deficits in short-term memory alone or have deficits in both short- term and long-term memory. The current work will also demonstrate how type and timing of training affects long-term retention in children with LI, which will lead to improved treatment of language impairment. Thus, the achievement of the specific aims will advance both research and clinical practice for children with LI.